Step 1: Jumbles reservoir walk. A gentle walk (mostly flat and pathed) around a scenic reservoir with some nice picnic points.
Step 2: Start at the Jumbles reservoir car park and cafe. Walk towards the cafe with the water on your left (you could go the other way around too). Follow the path towards the bridge that crosses the water. Take the bridge across.
Step 3: Once across, continue to follow the path. You will come out and go up a private road at some point, but there is an opening on the left to loop back towards the water. Then up the steps back to the car park.